1. Field of the Invention
This invention relates generally to splicing, and more specifically to an apparatus for splicing the trailing end of an expiring web to the leading end of a new stock roll.
2. Description of the Prior Art
Apparatuses and methods for splicing the trailing end of an expiring web to the leading end of a new web stock roll are generally well known in the art. For example, U.S. Pat. No. 2,149,832 discloses an apparatus and method in which the new stock roll is rotatably driven by an endless belt prior to the splicing operation to bring the rotational speed of the stock roll up to the speed of the expiring web. When the speeds are substantially equal, the new stock roll is moved into pressure engagement with a pressure roller over which the expiring web is trained. A paster on the new stock roll is provided with an adhesive on its inner surface for releasably holding the leading end of the stock roll to the adjacent web convolution. The paster is provided with adhesive on the outer surface thereof which adheres to the expiring web as the paster is moved through the nip formed by the pressure roller and new stock roll. The paster rips away from the adjacent convolution by virtue of a weakened section, thereby releasing the leading end of the new stock roll from the adjacent web convolution. One disadvantage of this splicing apparatus and method is that a plurality of separate drive belts must be provided to drive the new stock roll. In addition, the pasters have to be manually applied to the new stock roll which is time consuming. Another disadvantage is that the paster does not always rip along the weakened section and hence a portion thereof will remain on the stock roll. Consequently, one or more convolutions of the new stock roll are damaged by the paster portion before sufficient convolutions are wound on the portion to cover it and prevent damage to successive convolutions.
Another apparatus and method for splicing the trailing end of an expiring web to the leading end of a new stock roll is disclosed in U.S. Pat. No. 2,646,938. In this patent, the leading end of the new stock roll is V-shaped, and the tip thereof is secured to the adjacent web convolution by a pair of adhesive tabs. The edges of the remainder of the V-shaped leading end are provided with an adhesive. In addition, below the ends of the adhesive tabs are a pair of tear directing strips with adhesive thereon. The strips are positioned at an angle to the edges of the leading end with the inner tear strip ends situated inwardly and below the ends of the adhesive tabs. To achieve a splice, the expiring web is moved into low pressure engagement with the periphery of the new stock roll for initiating rotation of the new stock roll without adhering to the adhesive. When the stock roll is brought up to a predetermined speed, the splice is initiated by moving a brush which urges the expiring web into high pressure engagement with the periphery of the new stock roll. Accordingly, the adhesive and tear strips adhere to the expiring web and are torn away from the outer convolution of the stock roll and carried along the expiring web. The adhesive tabs remain on the web convolution. One disadvantage of this splicing apparatus is that it is difficult for the expiring web to rotatably drive the new stock roll without prematurely adhering the expiring web to the adhesive on the leading end of the new stock roll. In addition, a portion of the web end remains on the adjacent web convolution resulting in wastage of at least one web convolution. In addition, the adhesive tabs, adhesive and adhesive tear strips have to be manually applied to the web end which is tedious and time consuming.
Another web splicing apparatus for splicing the trailing end of an expiring web to the leading end of a new web roll is disclosed in U.S. Pat. No. 3,198,452. In this apparatus, the edge of the leading end of the new web roll is provided with adhesive along the entire width of the web except for a small section. Through this section an endless drive belt engages the web roll for rotatably driving the roll. The leading end of the web in this small section is provided with a splicing tape having raised non-adhesive strips thereon engageable by the drive belt. When the roll reaches a desired speed, a brush is actuated pushing the expiring web against the periphery of the new web roll and into pressure engagement with the adhesive and splicing tape. Once again, the disadvantage of this apparatus is that the adhesive and splicing tape has to be manually applied to the end of the web roll which is tedious and time consuming. In addition, a special web roll driving mechanism is required to drive the web roll. Applicant's improved apparatus and method for splicing the trailing end of an expiring web to the leading end of a new web roll is believed to obviate these and other disadvantages of known prior art web splicing apparatuses and methods.